This invention relates generally to product packaging systems. More particularly, it relates to formers used on automated equipment to configure sheet material into individual bags and fill the bags so formed with product.
For speed and economy of operation, the automated form/fill/seal type of bagging system is often chosen for bulk products, particularly foodstuffs. Material in sheet form (for example, a pre-printed, aluminized polymer sheet; TYVEK® spunbonded olefin, a synthetic material made of high-density polyethylene fibers; woven or knitted fabric material comprising natural fibers, synthetic fibers or a blend of natural and synthetic fibers; paper, including coated papers; cardboard and metal foils) is formed into a tube shape, provided with a longitudinal seal, filled with product and then sealed transversely to provide a closed bag. Such a process may be performed with continuous or near-continuous movement of packaging material through the apparatus.
As shown in FIG. 1, a typical product packaging system 100 comprises three major components: the product 105 to be packaged; packaging material 110 from which packages are formed; and former 115. Product 105 may be in a variety of physical forms including, for example, liquids, powders, solids and bulk material. Package material 110 is typically a thin film with text and graphics that identify the product (e.g., potato chips, coffee, candy, etc.) and the brand thereof. Former 115 is an assembly that manipulates package material 110 into the desired shape (e.g., a rectangular or elliptical bag) and configures the various seals that will close the bag, while the packaging system itself provides the product and actually seals package material 110 to form an enclosed volume (packages 120).
FIG. 2 illustrates a typical longitudinal-type packaging system 200. As shown, product 105 and packaging material 110 are introduced to former 115 where material 110 is shaped and aligned by wing 205 to conform about product filing tube 210 and to form a seam. The seam is longitudinally sealed by sealing device 215 so that material 110 forms a cylinder 220. Feeding device 225 pulls packaging material 110 (specifically cylinder 220) downward so that sealing/cutting device 230 may seal cylinder 220 to form product package 120.
Bag forming tools may be welded, formed or solid. Depending on the configuration of the former, a variety of seal configurations are available for the back or longitudinal seal including lap seals, reverse lap seals, fin seals, reverse fin seals, offset fin seals (both standard and reverse), pinch seals and combo seals (both standard and reverse).
Feeding device 225 typically comprises one or more pull-down belts that engage the packaging material between a rotating belt and the side of the product fill tube (or a replaceable wear strip thereon). Pull-down belts for bag-type automated packaging equipment are available in a variety of configurations including plain, grooved, with holes, with countersunk holes, slotted and with a stepped counterbore. Pull-down belts are also available in a variety of materials including, by way of example, polyurethane, natural and synthetic rubber, foam, high-density polyurethane foam, and silicone polymer.
Different bag forming collars are used on both vertical and horizontal form/fill/seal packaging machines to provide the desired type and size of package. Typically, an automated packaging system will comprise one or more removable, replaceable formers so that the packaging system can be used to fabricate and fill a variety of package types and sizes. In the past, aligning the former particularly with the pull-down belts and longitudinal seam former was a difficult and time-consuming task. Even a slight misalignment between the former and the rest of the packaging system can result in malformed packages and/or incomplete seals. The present invention solves this problem.
The fill tubes of former assemblies of the prior art typically were mounted to the base plate of the former with three or more bolts, each of which was inserted through a hole having a diameter larger than that of the bolt. This necessitated careful alignment of the fill tube each time it was removed for cleaning and replaced or when substituting a fill tube of a different size or configuration. The present invention solves this problem.